A multiple tube-type heat exchanger is also called a shell and tube type, and is, for example, a heat exchanger having a configuration where a heat transfer tube unit, in which multiple heat transfer tubes (tubes) are bound in a bundle, is accommodated inside a heat exchanger shell (shell) which is horizontally mounted. A process liquid to be cooled or heated and a temperature control solution for adjusting the temperature of the process liquid flow in such a multiple tube-type heat exchanger.
There is a case where a process liquid flows in a shell chamber inside the heat exchanger shell and a case where the process liquid flows in the heat transfer tubes. For example, the process liquid generally flows in the shell chamber in a case where the process liquid is a suspension including a large amount of hard particulate solids such as crushed slag and abrasive grains. That is because there are concerns about the inside of the heat transfer tubes wearing out due to abrasive properties of the suspension when the suspension passes through the heat-transfer tubes as the shapes of flow passages inside the heat transfer tubes are simpler than inside the shell chamber, and thus a flow rate tends to be higher in the heat transfer tubes.
Since the suspension flowing in the shell chamber comes into contact with the surfaces of the heat transfer tubes in such a manner, suspended matters gradually adhere to and deposit on the surfaces of the heat transfer tubes, thereby becoming a sticky scale. As the sticky scale covers the surfaces of the heat transfer tubes, a heat transferring performance decreases. For this reason, it is necessary to periodically clean the surfaces of the heat transfer tubes to remove the sticky scale. In the case of cleaning the heat transfer tubes, a water chamber-forming lid (end plate), which is one end of the heat exchanger shell, is removed to pull out the heat transfer tube unit inside the heat exchanger shell in an axis direction. The outer surfaces of the multiple heat transfer tubes are cleaned by a brush, high-pressure water injection, and chemical spraying.
In a multiple tube-type heat exchanger and a cleaning method for the same disclosed in PTL 1, the multiple tube-type heat exchanger adopts a structure of being rotatable about a central axis in advance, a shell chamber is filled with a certain amount of abrasive solid particles such as sand and metal balls, and the entire multiple tube-type heat exchanger is rotated under such conditions. Consequently, the sticky scale which is adhered to and is deposited on the surface of each heat transfer tube is removed due to the abrasive action of the abrasive solid particles.